Antimelanogenic effects of <Emphasis Type="Italic">Inula britannica</Emphasis> flower petal extract fermented by <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> KCCM 11613P

The inhibitory effects of Lactobacillus plantarum-fermented and non-fermented Inula britannica extracts on the tyrosinase activity were comparatively investigated to examine whether and how they improve the whitening activity, and the contents of total flavonoids and polyphenolics as bioactive compounds were determined. The skin whitening activity using in vitro or ex vivo tyrosinase and L-3,4-dihydroxyphenylalanine (L-DOPA) staining was examined. The total flavonoid content (TFC) was increased by 13.4% after 72 h-fermentation. The viabilities of the B16F10 cells treated with the fermented and non-fermented control extracts were 100.26% and 92.15% at 500 μg/ml, respectively. In addition, the inhibition of tyrosinase activity was increased by the fermented samples from 29.33% to 41.74% following fermentation for up to 72 h. The tyrosinase activity of the untreated control group was increased to 145.69% in B16F10 cells. The results showed that I. britannica fermented by L. plantarum dose-dependently inhibited tyrosinase activity, which was stimulated by α-melanocyte stimulating hormone. These results suggest that lactic fermented I. britannica extracts can be used as effective skin-whitening materials.     

U.S. and Korean children's comprehension of fraction names: a reexamination of cross-national differences

Two experiments tested the claim that the transparency of Korean fraction names promotes fraction concepts (Miura, Okamoto, Vlahovic-Stetic, Kim, & Han, 1999). In Experiment 1, U.S. and Korean first and second graders made similar errors on a fraction-identification task, by treating fractions as whole numbers. Contrary to previous findings, Korean children performed at chance when a whole-number representation was included. Nonetheless, Korean children outperformed their U.S. peers overall. In Experiment 2, U.S. children's performance improved when fraction names were used that explicitly referred to part-whole relations like Korean fraction names. U.S. children's scores actually exceeded those of Korean children. Thus, although the differences in fraction names may influence children's performance, this may not account for the reported cross-national differences.     

Motivation for physical activity in young people: entity and incremental beliefs about athletic ability

Three studies are reported of children and youth aged 11–19 years (n?=?3478) examining the nature of beliefs about athletic ability. Drawing on related research in academic, moral and stereotyping domains, development of a psychometric instrument assessing athletic ability beliefs is detailed. Support was found for a multidimensional hierarchical structure that is invariant across age and gender. Confirmatory factor analysis revealed a structure comprising two higher-order factors of entity and incremental beliefs underpinned by beliefs that athletic ability is stable and a gift (entity), and is open to improvement and can be developed through learning (incremental). Incremental beliefs, indirectly through a task goal orientation, and entity beliefs directly, predicted self-reported amotivation towards physical education and sport. On the other hand, enjoyment of physical activity in youth was predicted directly by task orientation and incremental beliefs. Predictions concerning the moderating role of perceived competence were not supported. Our findings highlight the importance of ability beliefs and goals in understanding the determinants of physical activity in children and youth.     

Young adults’ contact experiences and attitudes toward aging: age salience and intergroup anxiety in South Korea*

From the theoretical perspectives of communication accommodation and intergroup contact, this study examined South Korean young adults’ (N?=?301) perceptions of their communication experiences with a frequently-contacted grandparent, as well as attitudes toward older adults and own aging. Findings from structural equation modeling indicated that the participants’ attitudes towards older adults were positively predicted by contact frequency with the grandparent and negatively predicted by perceptions of the grandparent’s non-accommodative communication. Analyses of indirect effects revealed that young adults’ intergroup anxiety explained these associations. Although the direct effects of contact frequency and the grandparent’s non-accommodation on attitudes toward own aging were nonsignificant, the indirect effects through intergroup anxiety were significant. Moderation analysis indicated that these direct and indirect associations between non-accommodation and aging attitudes were significant only when age salience was low – a finding contrary to existing theory and research. Results are discussed in terms of intergenerational communication and culture, and theories of intergroup contact.     

Deciding How to Deceive: Differences in Communication and Detection Between Good and Bad Liars

To study deception, participants were randomly assigned the role of allocator or recipient in an ultimatum negotiation game. Allocators “earned” 7 dollars and divided the money between themselves and recipient and communicated the decision either face-to-face or through text chat. Recipients were unaware the amount the allocator had, and therefore, allocators could deceive. Most allocators used deception. We hypothesized that participants who self-identified as good liars would communicate more face-to-face than through text chat when deceiving, and this was supported for deceptive omission but not fabrications. Good liars were more likely to have their truths correctly detected than bad liars.     

“Science Talks” in Kindergarten Classrooms: Improving Classroom Practice Through Collaborative Action Research

In this study we described an action research project enacted by a veteran Kindergarten teacher (Sarah) in the context of a professional development program. Over the course of a year, Sarah collaborated with other teachers in a small group to investigate how to use “Science Talks” to promote student learning in Kindergarten classrooms. A Problem-Based Learning approach was adopted to guide the collaborative action research. Based on a rich set of data sources, we concluded that Sarah’s action research improved student learning and led to her own professional growth. We also identified important conditions in support of action research.     

TEXUS: A unified framework for extracting and understanding tables in PDF documents

Tables in documents are a widely-available and rich source of information, but not yet well-utilised computationally because of the difficulty in automatically extracting their structure and data content. There has been a plethora of systems proposed to solve the problem, but current methods present low usability and accuracy and lack precision in detecting data from diverse layouts. We propose a component-based design and implementation of table processing concepts which can offer flexibility and re-usability as well as high performance on a wide range of table types. In this paper, we describe a system named TEXUS which is a fully automated table processing system that takes a PDF document and detects tables in a layout independent manner. We introduce TEXUS’s own table processing specific document model and the two-phased processing pipeline design. Through an extensive evaluation on a dataset comprised of complex financial tables, we show the performance of the system on different table types.     

Secure chaotic communication based on extreme multistability

Extreme multistability is the coexistence of a large number of attractors which can be reached by varying initial conditions. In this paper we show how this fascinating phenomenon can be used for secure communication. The main advantage of the communication system based on extreme multistability over a conventional chaos-based communication system is its exceptionally high security. The proposed system consists of two identical six-order oscillators; one in the transmitter and another one in the receiver, each exhibiting the coexistence of a large number of chaotic attractors. The oscillators are synchronized using a private channel through one of the system variables, while the information is transmitted via a public channel through another variable. The information is encrypted by varying the initial condition of one of the state variables in the transmitter using a chaotic map, adhering message packages in a staggered form to the coexisting attractors within the same time series of another state variable, which leads to switching among the coexisting chaotic attractors. To ensure communication security, the duration of the packages is shorter than synchronization time, so that synchronization attacks are ineffective.     

Korean 4‐ to 11‐year‐old student conceptions of heat and temperature

The aim of the present study is to shed light on the conceptions that young students have of heat and temperature, concepts that are both important in school science curricula and closely related to daily life. The subjects of the study were students from a rural district in South Korea and they ranged in age from 4 to 11 years. Interviews were conducted with each student on the basis of questions on temperature, thermal insulation, and heat equilibrium. After calculating the frequency and percentage of student responses and analyzing the rationale for their answers, it was found that younger students tended to view temperature as “size” or a “summation of numbers.” This tendency gradually diminished in older students. Most students had alternative conceptions of thermal insulation regardless of age; however, reasoning differed according to age. Younger students displayed a greater tendency to view insulation as a material property, whereas older students showed a greater tendency toward rational heat and temperature conceptions. Most students did not have clear concepts of heat equilibrium regardless of age, but possessed numerous alternative conceptions. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 44: 284–302, 2007     

医学院校课程整合的经验教训:学生、课程负责人与改革领导者的观点

美国医学院校的课程整合改革方兴未艾.加州大学旧金山分校医学院从2001级新生开始对课程体系进行大幅调整,本研究调查了该校参与改革的不同群体,包括教育改革的领导者、受到直接影响的学生、新建课程的负责人等对课程改革的态度,了解其对课程整合实施一年内的成绩和挑战的看法.结果表明,他们对跨学科教学、跨学科系室协作、课程关联的建立、课程内容的排序及框架构建等四个主题有相同的看法,也有不小的分歧.